One of the most popular putters in professional golf looks to have received a makeover after Rory McIlroy and Jason Day were both spotted working with a prototype version of TaylorMade’s Spider putter during practice rounds at the Sentry Tournament of Champions.

The prototype McIlroy was seen using has a copper finish, slant neck and what looks to be two weight ports positioned in the main portion of the body. The previous version of Spider only had two ports located in back in the heel and toe position. The heel and toe ports appear to have been redesigned as well and look similar to what’s currently found on the scaled down Spider Mini.

For Day, switching to a tweaked Spider wouldn’t constitute as a life-changing switch. Day put the current version of Spider on the map when he switched to the red version in 2016 at RBC Heritage. He’s used the putter ever since and likely knows the ins and outs of the design better than almost any player on Tour.